Yes, what engine??
EDIT: 4.0l OHV, got it
Try turning the key on, count to 3 then turn key off
repeat 3 times, then crank engine.
Ford computers "prime" the fuel system by running the fuel pump for 2 seconds when key is first turned on, fuel pump doesn't start again until engine starts.
Your '99 needs 60psi of pressure at the fuel injectors for normal operation.
If you have a leak in the fuel system, then pressure goes away as engine sits, when you turn on the key you would get maybe 20psi of pressure back, fuel would just dribble into the intake while cranking, so it would take a few seconds to get enough fuel in the intake to start cold engine.
Priming the system 3 times raises the pressure to "normal".
A leak can be at the fuel pump so no visible signs, the fuel pump has a check valve/back flow preventer, this allows fuel to go out of the pump but not back in, if this valve leaks then fuel pressure is lost when pump is off, only way to test for this is with a fuel pressure gauge.
Ford systems also have a standard engine startup routine.
IAC valve should open all the way for start up, so idle should jump up to 1,500rpms
Then it will drop to "target" idle
If engine is warmed up then target is 800rpms for automatic
If engine is cold then target is around 1,100rpms based on coolant temperature, colder = higher idle, this is "choke mode", computer runs engine rich with high idle and advanced spark timing, just like a carb engine with choke plate closed.
The computer reads the coolant temp using the ECT(engine coolant temp) sensor, this is a TWO WIRE sensor, only used by the computer.
If you are not getting the higher idle on cold engine then I would look at the ECT sensor
There is a ONE WIRE sender, that looks similar, but is only used for the dash board temp gauge.
EDIT: on the 4.0l these are both located on the lower intake just above thermostat housing.
2 wire = sensor
1 wire = sender
The ECT sensors rarely fail, not never, rarely.
If ECT sensor was 'telling' computer that engine was always warmed up, then engine would be hard to start cold and wouldn't run well until it did warm up.
First step to check ECT sensor would be to find it and then unplug it.
Start engine, you should get a CEL(check engine light) because ECT is unplugged, that's good.
With no ECT data the computer will run a default rich air/fuel mix which should make engine easier to cold start
Last edited by RonD; 09-20-2014 at 11:01 AM.